This project involves the study of the inheritance patterns of well-defined vocalizations, particularly the isolation call, in selected primates. Cross-breeding of closely related species or subspecies with distinct vocal differences provides the opportunity for analysis of the parental contributions to hybrid vocal traits. Collaboration with experts in cellular genetics provides information regarding the transmission of genetic material to hybrid offspring as well as the genetic distances between members of the parental populations. A variety of primate species are examined for distinctive vocal traits and production of viable interspecific hybrids to evaluate their usefulness for studies in this area of genetic research.